MDM · Apple
DDM
Also known as: Declarative Device Management
Apple's deadline-driven device management model — a device receives a declaration of the desired end state and works toward it locally, rather than depending on a constant connection to a management server.
DDM — Declarative Device Management — is Apple's newer model for managing macOS devices, covering macOS 14 Sonoma and later. Rather than a management platform pushing commands and staying connected to walk a device through every step of an update, DDM hands the device a declaration: a desired end state and a deadline. The device's own operating system takes it from there, checking in periodically to report status rather than waiting on constant instruction.
For software updates specifically, this replaces the older command-and-wait model, where an MDM had to stay connected to babysit a multi-gigabyte installer through a major OS upgrade. Under DDM, a device can be told to reach a given macOS version by a given date; before that deadline the user can typically defer, and after it, the update installs and the machine restarts automatically, without the management platform needing to still be watching.
DDM is an account-level, opt-in capability in most MDM platforms — enabling it is a separate step from configuring an update policy, and a policy configured without DDM turned on for macOS 14+ devices will silently do nothing. It also only replaces part of the picture: some install-behavior settings, like forcing a restart, are MDM-only holdovers with no effect once a device is running under DDM. Getting the enforcement behavior you expect means knowing which engine a given device is actually running under.